The objective of this research is the elucidation of one of the methods by which the biosynthesis of collagen is controlled. The aspect of collagen biosynthesis examined is that of the synthesis of the primary proto-collagen protein. The particular aspect examined is that of estimating the regulation of the availability of the major amino acids of collagen, proline and glycine. Control of synthetic and degradative pathways of proline and glycine will be measured under conditions of collagen synthesis.